The battery life of cellular telephone devices having Wireless Local Area Network (WLAN) capabilities, in terms of standby time or talk time, is generally much shorter than the battery life of comparable cellular telephones devices that do not have WLAN capabilities. In addition to other factors, random access mechanisms utilized by WLAN systems, is a major contributor to the fast battery drainage of such devices. Some networking systems, such as systems in accordance with the IEEE 802.11 and 802.3 standards, rely on carrier-sense multiple access (CSMA) for channel access. In these systems, when one node (e.g., a wireless device) transmits communication packets, all nodes (e.g., wireless devices) within range of the transmitting node/device receive the packets. Then, in many systems, each node/device decodes the entire packet, e.g., by processing the entire packet at a Physical Layer (PHY) of the decoding device, and checks. After decoding the entire packet, a Medium Access Control (MAC) layer of the decoding device checks, for example, a MAC header of the packet, to determine whether the packet is intended for the decoding node, e.g., if the packet is a broadcast packet, a multicast packet intended for a network including the decoding node, or a unicast packet intended for reception by the decoding node. If the packet is intended to be received by the decoding node, a lower MAC layer of the decoding device passes the packet to an upper MAC layer for further processing. Otherwise, the lower MAC layer “drops” the packet from further processing. The lower MAC layer is usually implemented in micro-code (“uCode”), whereas the upper MAC layer is usually implemented in a driver of the decoding node/device.
However, in many of today's implementations, the data packet is dropped only after the entire packet has been decoded at the PHY layer and passed to the lower MAC layer. Because the PHY layer usually consumes most of the energy in a communication chipset and because communication chipsets generally spend more time receiving than transmitting, the energy consumed by reception of irrelevant packets has become a particularly significant factor in battery drainage. Furthermore, the trend of increased energy consumption in reception of irrelevant packets is becoming even more significant with the development of new communication devices with advanced capabilities that are able to receive larger communication packets.
Many packets are long packets, containing a substantial amount of information. For example, some communication technologies, such as the IEEE 802.11 and 802.3 standards, can transmit jumbo frames. For example, the IEEE 802.11n standard defines two frame aggregation schemes, that is, A-MSDU and A-MPDU, which have a frame size limit of 4K or 8K octets and 65,535 octets respectively.